Function            clear - clears a portion of the screen

  Syntax              void clear(int left, int top, int right,
                                 int bottom);

  Prototype in        video.h

  Remarks             clears a box of the screen via gotohv() and putk().
                      All screen coordinates are absolute.

  Return value        nothing.

  See also            cls(), gotohv(), putk()

  Example             #include <video.h>

                      main()
                      {
                           clear(0,0,79,3);    /* clear top 4 lines */
                      }